References of "De Clerck, Caroline"
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See detailSreening of essential oils against rice pathogens isolated from Madagascar
Mamiharisoa Razanakoto, Léa ULg; De Clerck, Caroline ULg; Massart, Sébastien ULg et al

Poster (2014, February 07)

Four predominant isolated pathogens have been identified during survey of rice diseases in three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv. oryzae and Pseudomonas ... [more ▼]

Four predominant isolated pathogens have been identified during survey of rice diseases in three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv. oryzae and Pseudomonas fuscovaginae and the fungi Alternaria sp. and Curvularia lunata. These pathogens are causing significant yield reduction on rice, which is the staple food in this country. After the identification of those pathogens, the objective of this work was to identify appropriate control measures against them. Plants extracts has been traditionally used to control diseases in other plant species. Nowadays, the problem of residues of phytopharmaceutical product, reinforce the need for research on the development of natural plant extracts to control plant diseases. Madagascar has many endemic plant of interest and we have evaluated the antimicrobial properties of essential oils from Malagasy plants. The main object of this study is the in-vitro screening of essential oils to control the pathogens isolated on rice in Madagascar. Thirty nine essentials oils from Madagascar had been tested. Activity of essentials oils on Pseudomonas fuscovaginae, Alternaria sp. and Curvularia lunata had been tested using broth media and on agar medium for Xanthomonas oryzae pv. oryzae. The growth of the pathogen (bacteria and conidia) in the presence of the essential oil was evaluated and compared to a control. Nine of the 39 essentials oils showed interesting antimicrobial activity with an efficiency more than 70% against at least one bacterial pathogen. One essential oil inhibited the growth of the two pathogens tested. For fungal pathogens, three essential oils presented an efficiency of more than 70% against at least one fungal pathogen. These results confirm that some essential oils present an interesting antimicrobial activity. The in-situ confirmation on plant of this activity is currently ongoing. [less ▲]

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See detailCombination of Genomic and Proteomic Approaches to Characterize the Symbiotic Population of the Banana Aphid (Hemiptera: Aphididae)
De Clerck, Caroline ULg; Tsuchida, Tsutomu; Massart, Sébastien ULg et al

in Environmental Entomology (2014)

Aphids are known to live in symbiosis with speciÞc bacteria called endosymbionts that have positive or negative impacts on their hosts. In this study, six banana aphid (Pentalonia nigronervosa Coquerel ... [more ▼]

Aphids are known to live in symbiosis with speciÞc bacteria called endosymbionts that have positive or negative impacts on their hosts. In this study, six banana aphid (Pentalonia nigronervosa Coquerel) strains from various geographical origins (Gabon, Madagascar, and Burundi) were screened to determine their symbiotic content, using complementary genomic (16S rDNA sequencing and speciÞc polymerase chain reaction) and proteomic (two-dimensional difference gel electrophoresis coupled with protein identiÞcation by matrix assisted laser desorption-ionization time-of-ßight mass spectrometry) approaches. Despite the geographical heterogeneity, the combined methods allowed us to identify the same two symbionts in the six aphids strains tested: Buchnera aphidicola and Wolbachia. Although B. aphidicola is found in almost all aphid species, the systematic presence of Wolbachia in banana aphids is particularly interesting, as this bacterium usually has a low prevalence in aphid species. Phylogenetic analyses showed that the Wolbachia sp. strain found in P. nigronervosa was very similar to the strain present in aphids of the genus Cinara, known to have developed a strong and long-term symbiotic association with Wolbachia. The high level of asexual reproduction in P. nigronervosa could be linked to the presence of Wolbachia, but its prevalence also suggests that this symbiotic bacterium could play a more essential role in its aphid host. [less ▲]

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See detailINCIDENCE DES MALADIES BACTERIENNES ET FONGIQUES DU RIZ A MADAGASCAR
Mamiharisoa Razanakoto, Léa ULg; De Clerck, Caroline ULg; Massart, Sébastien ULg et al

Poster (2013, December)

Le riz, c’est à la fois la culture la plus cultivée à Madagascar mais aussi la principale base de l’alimentation des malgaches. Même si le pays est à vocation agricole, l’autosuffisance alimentaire n’a ... [more ▼]

Le riz, c’est à la fois la culture la plus cultivée à Madagascar mais aussi la principale base de l’alimentation des malgaches. Même si le pays est à vocation agricole, l’autosuffisance alimentaire n’a jamais été atteinte, et l’importation de riz est toujours importante chaque année. Pour le riz, les maladies constituent le facteur entraînant la mauvaise qualité et la réduction des récoltes. C’est la raison qui nous amène à réaliser le suivi de la maladie de riz présent à Madagascar. L’incidence de la maladie a été évalué par l’observation visuelle des symptômes au champ et l’identité des pathogènes a été confirmée par les tests au laboratoire. Pour cela un échantillonnage a été réalisé dans les régions de Vakinankaratra, Analamanga et Atsinanana. Une enquête a été réalisée durant l’échantillonnage pour récolter les informations qui peuvent nous aider à l’identification de l’agent pathogène. L’isolement a été réalisé en utilisant les milieux standards pour bactéries et pour champignons. Les isolats ont été ensuite identifiés par l’observation des colonies sur boite de Pétri, par des observations microscopique des cellules en présence de différents colorants. Elles ont ensuite été identifiées par analyse moléculaire par séquençage.Dans les régions du haut plateau : les symptômes trouvés sont très variés et l’incidence de chaque symptôme est faible sauf le flétrissement des feuilles de riz. Dans la région Atsinanana, les symptômes trouvés ne varient pas et l’incidence est proche de 100 %. L’isolement des microorganismes à partir d’échantillons de chacune de ces régions confirme les résultats obtenus : Xanthomonas oryzae pv. oryzae correspondait à l’espèce pathogène dominante pour les hauts plateaux tandis que Curvularia lunata correspondait à l’espèce pathogène dominante pourAtsinanana. Ces différences trouvent probablement leur origine dans les conditions climatiques et le mode de culture très différentes entre cette région côtière et les hauts plateaux. [less ▲]

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See detailFirst report of banana mild mosaic virus infecting plantain in Ivory Coast
Kouadio, Kouakou Théodore ULg; Agneroh, Thérèse Atcham; De Clerck, Caroline ULg et al

in Plant Disease (2013), 97(5), 693

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See detailSURVEY OF RICE DISEASES IN THREE REGIONS IN MADAGASCAR
Mamiharisoa Razanakoto, Léa ULg; De Clerck, Caroline ULg; Zalmine, Francia et al

Poster (2013, February 08)

Rice (Oryza sativa) is the most cultivated crop and the staple food in Madagascar. However, the country has never achieved food self-sufficiency and continues to import rice abroad. Rice diseases are one ... [more ▼]

Rice (Oryza sativa) is the most cultivated crop and the staple food in Madagascar. However, the country has never achieved food self-sufficiency and continues to import rice abroad. Rice diseases are one of the factors limiting rice production and causing significant yield reductions. Our study aims to identify the rice pathogens present in three region of Madagascar: two of these regions (Analamanga and Vakinankaratra) are located in upland region when the last (Atsinanana) is located in coastal regions. Fifty five (55) rice samples were collected and cultured on standard media. A survey questionnaire was also conducted with the farmers in order to collect information about the context in which the diseases appeared. Micro-organisms isolated were identified by morphological characteristics for fungi, gram stain and anaerobic growth test for bacteria. In addition, molecular DNA characterization was performed by PCR using universal primers for both fungi and bacteria. The amplicons obtained were sequenced and analyzed by BLAST. In Analamanga and Vakinankaratra, Alternaria sp. and Xanthomonas oryzae pv. oryzae were pre-dominant. In the Atsinanana region, however, Curvularia lunata and Pseudomonas fuscovaginae were the most present. The weather in upland regions is indeed warm and humid in summer, dry and cold in winter which favours Xanthomonas oryzae pv. oryzae and Alternaria sp.growth. Moreover, irrigation is practiced in those regions which can explain the spread of the diseases. The weather in coastal region is warm and humid all year long which tend to favor weed development all year, serving as alternative hosts for Pseudomonas fuscovaginae and Curvularia lunata in interseason. [less ▲]

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See detailSurvey of rice diseases in three regions in Madagascar
Razanakoto Mamiharisoa, Lea; De Clerck, Caroline ULg; Zalmine, F. et al

Poster (2013, February 08)

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See detailDevelopment of a test to assess the Banana Bunchy Top Virus transmissibility through direct analysis of its aphid vector Pentalonia nigronervosa
De Clerck, Caroline ULg; Francis, Frédéric ULg; Lepoivre, Philippe ULg et al

in Communications in Agricultural and Applied Biological Sciences (2013, February), 78(1), 49-54

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See detailRole of satellite RNAs in cucumber mosaic virus-host plant interactions. A review
Kouadio, Kouakou Théodore ULg; De Clerck, Caroline ULg; Agneroh, Thérèse Atcham et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(4), 644-650

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See detailDiagnosis of Pathogens responsible of pre-and post-harvest rice diseases in Madagascar
Razanakoto Mamiharisoa, Lea; De Clerck, Caroline ULg; Parisi, Olivier ULg et al

Poster (2013)

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See detailPrincipal disease and Insect pests of Jatropha curcas L. in the lower valley of the Senegal river
Terren, Marieke ULg; Mignon, Jacques ULg; De Clerck, Caroline ULg et al

in Tropicultura (2012), 30(4), 222-229

Jatropha curcas L. seed oil is proven to be toxic to many microorganisms, insects and animals. Despite its toxicity, Jatropha is not pest and disease resistant. The following major pests and diseases ... [more ▼]

Jatropha curcas L. seed oil is proven to be toxic to many microorganisms, insects and animals. Despite its toxicity, Jatropha is not pest and disease resistant. The following major pests and diseases affecting Jatropha in the lower valley of the Senegal river have been identified: the leaf miner Stomphastis thraustica (Meyrick, 1908) (Lepidoptera, Gracillariidae), the leaf and stem miner Pempelia morosalis (Saalmuller, 1880) (Lepidoptera, Pyralidae) and the shield-backed bug Calidea panaethiopica (Kirkaldy, 1909) (Heteroptera, Scutelleridae), which can cause flower and fruit abortion. Damage from these pests was particularly great during the second year after the plantations were set up (2009) and before later receding. Nevertheless, the worst attacks were caused by a vascular disease transmitted through the soil, which killed 65% of the plants in four years. It is mainly characterised by collar and root rot, which causes foliage to yellow and wilt, before the plant eventually dies. These threats should increase if larger areas are planted with Jatropha. Considering the scale of the damage caused by these attacks in Bokhol, the development of an integrated pest management programme adapted to the local context should be considered. [less ▲]

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See detailBanana macropropagation: an alternative way of producing seedlings for the farmers in Burundi
Nintije, Pierre ULg; De Clerck, Caroline ULg; Bigirimana, Joseph et al

Poster (2012, May 22)

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